Sciencemadness Discussion Board

silver phosphate plus nitric acid yields...

unregistered - 26-9-2004 at 17:14

i've been tinkering with this equation and i have come up with two answers:

Ag2 + HNO3 -> AgNO3 + H2CO3

and

Ag2 + HNO3 -> AgNO3 + CO2 + H2O

according to my sources, the carbonic acid will decompose and form water and carbon dioxide, but i thought that carbonic acid would be enough.

which answer is correct and how did you arrive at it?

The_Davster - 26-9-2004 at 17:36

I am sorry, but I fail to understand your question. What are you asking? And where does the carbonate/CO2 come from?, there is no carbon containing molecule in the reactant side.

The reaction of silver with nitric acid is
Ag+2HNO3 --> AgNO3 +NO2 + H2O
This can be arrived at by using a redox table.

oh crap...

unregistered - 26-9-2004 at 17:39

the first side was supposed to read:

Ag2CO3


i forgot the CO3.

The_Davster - 26-9-2004 at 17:46

In that case the reaction is
Ag2CO3 +2HNO3-->2AgNO3 + CO2 +H2O

And the title of this thread reads "silver phosphate plus nitric acid yields..." yet the reaction you wrote out is silver carbonate plus nitric acid. So are you also in need of the reaction of nitric with silver phosphate?

thanks...

unregistered - 26-9-2004 at 18:25

but no. you see i was also doing other reactions while i was posting that one that's why i made so many mistakes.


anywho, i have one other q; when you have a silver compound and you mix it with nitric acid, will the silver always separate from its compound and form silver nitrate with the nitric acid? and if so, will the remaining hydrogen ion always attach to the other half of the silver compound?

e.g., will AgCl, AgI, Ag3PO4, AgBr, and AgCrO4 all form AgNO3, and then the H+ will attach to the remaining Cl, I, PO4, Br, and PO4?

neutrino - 27-9-2004 at 13:35

If there are no ions present that will form a percipitate, you will just get a solution full of ions. Then you'd just have the standard methods of separating out compounds: crystilization, crash percipitation, distillation (It'll most likely have to be a vacuum distillation, as AgNO<sub>3</sub> decomposes easily), etc. If you want just the other compound, you could heat the solution and wait for the solver nitrate to decompose and Ag<sub>2</sub>O to percipitate.

[Edited on 27-9-2004 by neutrino]

[Edited on 27-9-2004 by vulture]

hmmmm.....

unregistered - 27-9-2004 at 18:55

all of the compounds that i posted formed precipitates, and i was told to write net ionic equations for all of them. however, i am confused because it looks as though all of the compounds will give me AgNO3, with hydrogen ions and ions of the other half of the original silver compounds.


finally, is chem tutor any good (chemtutor.us)???

BromicAcid - 27-9-2004 at 19:08

AgI, AgCl, and AgBr will not appreciably undertake any reaction when mixed with HNO3 under normal circumstances. There are other reaction pathways that would occur if they were left for quite some time, but the reaction:

AgX(s) + HNO3(aq) <---> AgNO3(aq) + HX(aq)

Is shifted strongly to the left.

Silver phosphate and silver chromate are soluble in acids however. But it is not a full reaction, just an equilibrium that exists:

Ag3PO4(s) + 3HNO3(aq) <----> Ag(+) + PO4(3-) + H(+) + NO3(-)

Same with the chromate or dichromate, whichever you ment. It's just a soup that you end up with, not a predominate reaction to my knowledge, although I could be wrong on an exact reaction involving the phosphate and chromate.

These reactions are different entirely from the carbonate reaction that you started out with, that had a driving force behind it, loss of CO2 along with the normal basicity associated with it. These are usually going to be no reaction or a soup of products.